This invention relates generally to a graphical user interface of a data processing system. More particularly, the invention relates to a technique which determines whether scrolling capability in a target window should be provided during a drag and drop operation.
It is well known to provide a Graphical User Interface (GUI) to allow a user to control a computer system. A graphical user interface is used to present items which may be selected by the user and the results of such selection on the display. In a graphical user interface applications and data files are generally represented by a plurality of graphical objects such as windows or icons. It is known to allow a user to move graphical objects within a window or between windows through a "drag and drop" operation. During a drag and drop operation, the user selects an item such a data file, represented by a graphical object such as an icon by moving the mouse pointer to the graphical object in the interface. Then, one or more buttons on the mouse are depressed and held while the user moves the mouse pointer through the GUI to the desired position. The desired position may simply be for a more aesthically pleasing arrangement of the interface, or, in the case of a transfer between windows, may represent a transfer of data between applications or data files. The user then releases the button or buttons and the graphical object is "dropped" and placed at the new position in the interface. Logical changes are also made as a result of this operation such as storing the new position in the data structures which support the GUI as well as placing the data file represented by the icon into a new file structure, represented by the window to which the icon was moved.
Where the drag and drop operation involves a transfer from window to window and the space allocated for each window is not sufficient to display the entire window user interface, the drag and drop operation is somewhat cumbersome, particularly when the desired location in the target window is not displayed. User can use the scroll bar in target window to move the desired position into the target window's display space. Then, the object to be moved is dragged and dropped from the source location onto the target position. Alternatively, if the target position is not visible in the target window, the icon may be dropped at an arbitrary position in the target window. Then the user may use the scroll bar and drag and drop techniques together to move the icon to the target position.
This invention teaches an improved method of drag-drop operations.